The invention relates to a method for operating a drive device of a motor vehicle, which drive device has an internal combustion engine, an electric machine and a dual-clutch transmission, wherein the dual-clutch transmission has two clutches by which it can be connected to the internal combustion engine, wherein in a driving mode at least the internal combustion engine is actuated in order to generate a target drive torque, and is connected to the dual-clutch transmission by one of the clutches, and wherein the clutches are activated in opposite directions for a gear shifting process.
In addition, the invention relates to a device for operating the drive device described above as well as to a corresponding drive device.
Methods, devices and drive devices of the type mentioned at the beginning are basically known from the prior art. In particular, what are referred to as hybrid drive devices which, in addition to an internal combustion engine, have at least one electric machine are being used increasingly in motor vehicle construction. Such drive devices permit different types of driving modes to be implemented, such as for example a purely electric mode, a purely internal combustion engine mode and a mixed mode in which the drive torque of the motor vehicle is generated jointly both by the electric motor and by the internal combustion engine. Because the electric motor can also be operated as a generator, it is possible here to charge a vehicle battery of the motor vehicle electrically by load point shifts of the internal combustion engine, or to feed electrical energy into the battery during a braking process. The drive machines, electric motor and internal combustion engine are usually not connected directly to driven wheels of the motor vehicle but instead with the intermediate connection of a transmission having a variable transmission ratio. In the simplest case, this transmission is an automated transmission with a plurality of permanently predefined transmission ratios. In order to reduce shift times, it is also known to provide dual-clutch transmissions which have two transmission shafts which run one inside the other and are each connected to a clutch by which the respective transmission shaft can be operatively connected to the internal combustion engine, such that a torque which is provided by the internal combustion engine can be transmitted to the respective transmission shaft. By advantageous actuation of the clutches in opposite directions it is possible here for a gear on one of the transmission shafts to be changed while a drive torque is transmitted from the internal combustion engine to the driven wheels by the other transmission shaft. By simultaneously engaging the one clutch and disengaging the other clutch it is therefore possible for a gear shifting process to take place virtually without a shifting delay, which would give rise to an interruption in the tractive force. The electric machine can be arranged at different locations of such a drive device in order to generate an additional positive or negative machine torque which is transmitted to the driven wheels.